The Wellington Girls' College cyclist has been putting on extra layers of clothing in preparation for her international debut.

She will head to Toowoomba, in Queensland, next week with the New Zealand under-19 team to compete at the Oceania road cycling championships.

"We won't have much time to acclimatise, so I have been putting on extra layers to heat things up a bit more," Johnson said.

"I'm not sure what it's going to be like [in Toowoomba] and it hasn't been too hot there recently - in the high 20s. But I don't tend to do well in the heat."

Selection in the Oceania team represents a significant milestone for Johnson, a year 12 student and the youngest member of the women's junior team for the championships.

"I've never raced overseas before and it's quite a big step up for me. It's the first time I've represented New Zealand as well, so I'm a bit nervous - well quite nervous. But it's really exciting as well."

The under-19 section begins with a 13km individual time trial on February 21, with a 75km road race the following day.

"I don't want to go there and expect too much of myself," Johnson said.

"I'm not sure what to expect as I don't know the opposition or the course and I may have to work for somebody else [in the New Zealand team] in the road race."

The five members in the Kiwi squad will compete as a team in the road race.

Making the Oceania team looked some distance away when Johnson had to pull out of the novice tour of Manawatu in early December with a stomach bug. "I ended up in hospital on a drip and it took a while to get over it."

However, Johnson had been named in the national under-19 development squad last September, after two years in the under-17 squad, and made a good fist of her open-grade debut, in the HUB tour in Hawke's Bay last month.

Johnson finished third in two of the four stages and came 10th overall, after finishing 11th in both the time trial and the final stage.

"I went better than I expected and was actually quite pleased with my time trial because I dropped a chain on the last hill. I got it up pretty quickly but still lost a decent amount of time. You lose your rhythm and have to work a bit to get back up to speed.

"After that [the HUB Tour], I thought I may have had a decent chance of making the team for Oceania."

After returning from Queensland, Johnson will prepare for the under-19 national track championships, in Cambridge, from March 13 to 16.